14/05/2019 4 min

LEDs: ANSES’s recommendations for limiting exposure to blue light

Now that the use of LEDs for lighting has become widespread and the number of LED objects has proliferated, ANSES is publishing an update of its 2010 expert appraisal on the health effects of LEDs in light of new scientific knowledge. The Agency confirms the toxicity of blue light on the retina and highlights the biological rhythm and sleep disruption associated with exposure to blue light in the evening or at night, particularly via screens and especially for children. The Agency therefore recommends limiting the use of LED devices with the highest blue-light content, especially for children, and reducing light pollution as much as possible to preserve the environment.

Against a backdrop of energy-saving policies and the phasing-out of traditional lamps (incandescent and halogen lamps), LEDs have seen strong growth due to their energy-efficient performance. In a few decades, therefore, the population's exposure to blue light has increased sharply, especially in the evening with artificial lighting or screens rich in blue light. This is due to the unique technological characteristics of LEDs, which enable them to emit more short-wavelength light, known as "blue-rich". This lighting is more intense than other light sources, and can have effects on human health and the environment.

When this technology was initially deployed, ANSES's first expert appraisal underlined the retinal toxicity of the blue light contained in LED lighting systems and recommended adapting the regulatory and normative framework. As a result, for domestic lighting, only LED lamps in risk groups 0 or 1 (in accordance with the NF-EN-62471 standard on photobiological safety) are currently accessible to the general public. The most at-risk lighting systems (groups 2 and 3) are reserved for professional use under conditions that guarantee worker safety.

Today, ANSES is publishing a new expert appraisal covering all LED systems and taking into account all the scientific data acquired since 2010.

Demonstration of new effects associated with the blue light of LEDs

The new scientific data confirm the 2010 result regarding the toxicity of blue light to the eye, which can lead to failing eyesight. They show short-term phototoxic effects associated with acute exposure and long-term effects associated with chronic exposure, which increase the risk of developing age-related macular degeneration (ARMD). "Warm white" domestic LED lighting is no different from traditional lighting and has a low risk of phototoxicity. On the other hand, other types of LED lighting systems, such as hand-held lamps, vehicle lights, decorations or toys, may emit particularly blue-rich light and belong to risk group 2, and yet they are not covered by the current regulations.

In addition, the expert appraisal showed that even very low levels of exposure to blue light in the evening or at night disrupt biological rhythms and therefore sleep. ANSES stresses that the screens of computers, smartphones and tablets are major sources of blue-rich light, and children and adolescents, whose eyes do not fully filter blue light, are a particularly susceptible population.

The expert appraisal also showed that a high proportion of LED lamps have significant variations in light intensity. Some groups of people, such as children, adolescents and workers, may be more susceptible to the potential effects of this light modulation: headaches, visual fatigue, risk of accidents, etc.

Adapt the regulations and improve the information provided to the public about the risks associated with exposure to blue light

In view of the results of its expert appraisal, ANSES is making a series of recommendations to limit the population's exposure to blue light. The Agency reiterates the importance of favouring "warm white" domestic lighting (colour temperature below 3000 K). To prevent the disruptive effect on biological rhythms, it recommends limiting the exposure of people – children in particular – to the blue-rich light of LED screens (mobile phones, tablets, computers, etc.) before bedtime and at night.

In addition, ANSES recommends adapting the regulatory framework for all LED systems, particularly in order to:

  • restrict the sale of LED objects to the general public to those in photobiological risk group 0 or 1;
  • limit the light intensity of vehicle lights, while guaranteeing road safety;
  • minimise the temporal modulation of the light emitted by all light sources (lighting, screens, other LED objects).

Moreover, with regard to the protective devices available to the general public, such as treated lenses, protective glasses or specific screens, the Agency stresses that their effectiveness against the effects of blue light on the retina varies widely. Moreover, their effectiveness at preserving circadian rhythms has not yet been proven. ANSES encourages the establishment of standards defining performance criteria for protective equipment in relation to blue light.

An impact on biodiversity and the environment

Concerning the environment, the available studies mainly focus on artificial light at night in general and not specifically on LEDs. Regardless of the studied ecosystem, scientific knowledge consistently shows an increase in mortality and a decline in the diversity of the animal and plant species studied in environments lit at night, including by LED lighting systems. The Agency recommends strengthening regulations to limit light pollution, while ensuring public safety.